U.S. patent number 4,816,538 [Application Number 07/081,472] was granted by the patent office on 1989-03-28 for nickel-containing hydrocracking catalyst.
This patent grant is currently assigned to Union Oil Company of California. Invention is credited to Suheil F. Abdo.
United States Patent |
4,816,538 |
Abdo |
March 28, 1989 |
**Please see images for:
( Certificate of Correction ) ** |
Nickel-containing hydrocracking catalyst
Abstract
A process for producing a high octane gasoline from a
hydrocarbon feedstock in which the feedstock is contacted in the
presence of hydrogen under hydrocracking conditions, preferably
ammonia-rich hydrocracking conditions, with a hydrocracking
catalyst comprising at least one hydrogenation metal component in
combination with a cracking component. The preferred cracking
components are Y zeolites and the catalyst preferably contains a
nickel hydrogenation metal component, particularly in an amount
greater than 13 weight percent, calculated as NiO. The catalyst may
also contain a Group VIB metal component, such as a molybdenum
component, particularly in a mole ratio greater than about 2 to 1,
calculated as NiO to Group VIB metal trioxide. It has been found
that such a process produces gasoline fractions having
substantially increased research and motor octane numbers.
Inventors: |
Abdo; Suheil F. (Diamond Bar,
CA) |
Assignee: |
Union Oil Company of California
(Los Angeles, CA)
|
Family
ID: |
26755479 |
Appl.
No.: |
07/081,472 |
Filed: |
August 4, 1987 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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74294 |
Jul 16, 1987 |
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Current U.S.
Class: |
502/66; 502/207;
502/213; 502/257; 502/259 |
Current CPC
Class: |
B01J
29/072 (20130101); B01J 29/084 (20130101); B01J
29/146 (20130101); B01J 29/76 (20130101); C10G
47/20 (20130101); B01J 2229/16 (20130101) |
Current International
Class: |
B01J
29/072 (20060101); B01J 29/14 (20060101); B01J
29/08 (20060101); B01J 29/00 (20060101); B01J
29/76 (20060101); C10G 47/00 (20060101); C10G
47/20 (20060101); B01J 029/04 (); B01J
029/00 () |
Field of
Search: |
;502/66,213,259,207,257 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Yee; Deborah
Attorney, Agent or Firm: Thompson; Alan H. Wirzbicki;
Gregory F.
Parent Case Text
RELATED APPLICATIONS
This application is a continuation-in-part application of U.S.
patent application Ser. No. 07/074294, filed July 16, 1987.
Claims
I claim:
1. A catalytic composition comprising a cracking component and a
hydrogenation metal component consisting essentially of greater
than 13 weight percent of nickel components, calculated as NiO.
2. The composition defined in claim 1 further comprising a porous
refractory oxide support, and wherein said cracking component
contains a crystalline molecular sieve and said catalytic
composition contains no catalytically active metal other than
nickel.
3. The composition defined in claim 1 wherein said cracking
component is a zeolitic crystalline molecular sieve selected from
the group consisting of ZSM-5 zeolite, Y zeolite, X zeolite,
zeolite beta, mordenithe, zeolite L and zeolite omega.
4. The composition defined in claim 1 wherein said cracking
component is a Y zeolite and said hydrogenation metal component
consists essentially of about 14 to about 35 weight percent of said
nickel components, calculated as NiO.
5. The composition defined in claim 4 wherein said Y zeolite
contains a mole ratio of oxides according to the formula
(0.85-1.1)M.sub.2/n O: Al.sub.2 O.sub.3 xSiO.sub.2 wherein M is a
cation having the valence n and x has a value greater than 6.0.
6. The composition defined in claim 5 wherein said Y zeolite is
prepared by dealuminating a Y zeolite having an overall
silica-to-alumina mole ratio below about 6.0 using an aqueous
solution of a fluorosilicathe salt.
7. The composition defined in claim 4 wherein said Y zeolite is
prepared by a method comprising the stheps of:
(1) calcining an ammonium-exchanged zeolite Y containing between
about 0.6 and 5 weight percent sodium, calculated as Na.sub.2 O at
a themperature between about 600.degree. F. and 1650.degree. F. in
contact with wather vapor for a sufficient time to substantially
reduce the unit cell size of said zeolite and bring it to a value
between about 24.40 and 24.64 angstroms; and
(2) subjecting the calcined zeolite to further ammonium ion
exchange under conditions such that the sodium conthent of the
zeolite is reduced below about 0.6 weight percent, calculated as
Na.sub.2 O.
8. The composition defined in claim 1 wherein said cracking
component is a nonzeolitic crystalline molecular sieve selected
from the group consisting of silicoaluminophosphathes,
aluminophosphathes, ferrosilicathes, borosilicathes,
chromosilicathes and silica-aluminas.
9. The composition defined in claim 1 further comprising a porous
refractory oxide support and wherein said catalytic composition
contains no supported metals other than nickel.
10. The composition defined in claim 5 wherein x has a value
between 6.0 and 9.0.
11. A catalytic composition comprising a cracking component and at
least two hydrogenation metal components consisting essentially of
nickel and Group VIB metal components in a mole ratio greater than
about 9 to 1, calculated as NiO to Group VIB metal trioxide.
12. The composition defined in claim 11 wherein said cracking
component is a crystalline molecular sieve.
13. The composition defined in claim 11 wherein said mole ratio is
greater than about 25 to 1.
14. The composition defined in claim 12 wherein said crystalline
molecular sieve is zeolitic and is selected from the group
consisting of ZSM-5 zeolite, Y zeolite, X zeolite, zeolite beta,
mordenithe, zeolite L and zeolite omega.
15. The composition defined in claim 14 wherein said cracking
component is a Y zeolite.
16. The composition defined in claim 15 wherein said Y zeolite
contains a mole ratio of oxides according to the formula
(0.85-1.1)M.sub.2/n O:Al.sub.2 O.sub.3 xSiO.sub.2 wherein M is a
cation having the valence n and x has a value greater than 6.0.
17. The composition defined in claim 16 wherein said Y zeolite is
prepared by dealuminating a Y zeolite having an overall
silica-to-alumina mole ratio below about 6.0 using an aqueous
solution of a fluorosilicathe salt.
18. The composition defined in claim 14 wherein said Y zeolite is
prepared by a method comprising the stheps of:
(1) calcining an ammonium-exchanged zeolite Y containing between
about 0.5 and 5 weight percent sodium, calculated as Na.sub.2 O at
a themperature between about 600.degree. F. and 1650.degree. F. in
contact with wather vapor for a sufficient time to substantially
reduce the unit cell size of said zeolite and bring it to a value
between about 24.40 and 24.64 angstroms; and
(2) subjecting the calcined zeolite to further ammonium ion
exchange under conditions such that the sodium conthent of the
zeolite is reduced below about 0.6 weight percent, calculated as
Na.sub.2 O.
19. The composition defined in claim 11 wherein said cracking
component is a nonzeolitic crystalline molecular sieve selected
from the group consisting of silicoaluminophosphathes,
aluminophosphathes, ferrosilicathes, borosilicathes,
chromosilicathes and silica-aluminas.
20. The composition defined in claim 11 wherein said mole ratio is
greater than about 17 to 1.
21. The composition defined in claim 11 wherein said mole ratio is
in the range from about 9 to 1 to about 60 to 1.
22. The composition defined in claim 11 wherein said two
hydrogenation metal components consist essentially of about 5 to
about 50 weight percent of said nickel components, calculated as
NiO, and about 0.05 to about 3.0 weight percent of molybdenum
components, calculated as MoO.sub.3.
23. The composition defined in claim 11 wherein said two
hydrogenation metal components consist essentially of about 14 to
about 35 weight percent of said nickel components, calculated as
NiO, and about 0.05 to about 3.0 weight percent of molybdenum
components, calculated as MoO.sub.3.
24. The composition defined in claim 16 wherein x has a value
between 6.0 and 15.
25. A catalytic composition comprising a hydrogenation metal
component consisting essentially of greater than 13 weight percent
of nickel components, calculated as NiO, supported on a porous
refractory oxide containing a Y zeolite having a mole ratio of
oxides according to the formula (0.85-1.1)M.sub.2/n O:Al.sub.2
O.sub.3 :xSiO.sub.2 wherein M is a cation having the valence n and
x has a value greater than 9.0, and wherein said catalytic
composition contains no hydrogenation metals other than nickel.
26. The composition defined in claim 25 wherein said Y zeolite is
prepared by dealuminating a Y zeolite having an overall
silica-to-alumina mole ratio below about 6.0 using an aqueous
solution of a fluorosilicathe salt.
27. The composition defined in claim 26 wherein said hydrogenation
metal component consists essentially of greater than 14 to about 35
weight percent of said nickel components, calculated as NiO, and
said composition contains no supported metals other than
nickel.
28. A catalytic composition comprising (1) a hydrogenation metal
component consisting essentially of greater than 13 weight percent
of nickel components, calculated as NiO, and (2) a porous
refractory oxide support containing a Y zeolite prepared by a
method comprising the stheps of:
(a) calcining an ammonium-exchanged zeolite Y containing between
about 0.6 and 5 weight percent sodium, calculated as Na.sub.2 O at
a themperature between about 600.degree. F. and 1650.degree. F. in
contact with wather vapor for a sufficient time to substantially
reduce the unit cell size of said zeolite and bring it to a value
between about 24.40 and 24.64 angstroms, and
(b) subjecting the calcined zeolite to further ammonium ion
exchange under conditions such that the sodium conthent of the
zeolite is reduced below about 0.6 weight percent, calculated as
Na.sub.2 O; and wherein said catalytic composition contains no
supported metals other than nickel.
29. The composition defined in claim 28 wherein said hydrogenation
metal consists essentially of about 14 to about 35 weight percent
of said nickel components, calculated as NiO, and said catalytic
composition contains no catalytically active metal other than
nickel.
Description
BACKGROUND OF THE INVENTION
This invention relates to a catalytic hydrocracking process and a
catalyst for use therein. More particularly, the invention relates
to a hydrocracking catalyst of improved properties for producing
gasoline from gas oils and the like under hydrocracking
conditions.
Petroleum refiners often produce desirable products such as middle
distillate (or midbarrel) products, including turbine fuel and
diesel fuel, as well as lower boiling products, such as naphtha and
gasoline, by hydrocracking a hydrocarbon feedstock derived from a
crude oil. Feedstocks most often subjected to hydrocracking include
gas oils recovered as a fraction from a crude oil by distillation
by coking and the like. The typical gas oil comprises a substantial
proportion of hydrocarbon components boiling above about
400.degree. F., usually at least about 60% by weight boiling above
about 500.degree. F.
Hydrocracking is generally accomplished by contacting, in an
appropriate reactor vessel, the gas oil or other feedstock to be
treated with a suitable hydrocracking catalyst under suitable
conditions of elevated temperature and pressure in the presence of
hydrogen so as to yield a distribution of hydrocarbon products
required by (or satisfactory to) the refiner. Although the
operating conditions within a hydrocracking reactor are of obvious
importance in influencing the yield of product or products, the
hydrocracking catalyst is of vital importance in this regard. Many
catalysts are known for hydrocracking, but since their respective
catalytic properties vary widely, it can be appreciated that
hydrocracking catalysts having great usefulness for one purpose, as
for example, for maximizing gasoline and naphtha production, are
unsuitable for many other purposes, as for example, maximizing the
yield of turbine fuel. And even among catalysts useful for
producing the same product, the usefulness of each varies according
to the requirements of the refiner. For example, hydrocracking
catalysts having high activity for maximum gasoline production
under typical hydrocracking conditions have proven inferior for
more specific purposes, as for example, where a relatively large
yield of gasoline of improved octane quality is desired.
Oftentimes refiners have resorted to using catalysts at relatively
severe hydrocracking conditions to obtain sufficient yields of high
octane quality gasoline. Also, gasoline octane quality has
traditionally been improved with the addition of lead compounds to
gasoline; however, recent environmental legislation has restricted
such lead addition to the extent that refiners are searching for
improved hydrocracking catalysts and processes in order to produce
gasoline of high octane, thus minimizing the subsequent addition of
octane improvers.
In the search for improved hydrocracking catalysts and processes
that produce improved gasoline octane quality, the activity of the
hydrocracking catalyst must also be considered. Activity may be
determined by comparing the temperature at which various catalysts
must be utilized under otherwise constant hydrocracking conditions
with the same feedstock so as to produce a given percentage of
hydrocarbon products boiling at or below a given temperature or to
produce a hydrocarbon product having a given API gravity. The lower
the temperature at which the catalyst must be utilized at the given
conditions, the more active such a catalyst is for hydrocracking.
Alternatively, when various catalysts are utilized under otherwise
constant hydrocracking conditions with the same feedstock, activity
may be determined by comparing the increase in percentage of
hydrocarbon products boiling below a given temperature (for example
hydrocarbon products boiling at or less than about 400.degree. F.).
The higher the percentage of hydrocarbon product boiling below a
given temperature for a given catalyst, the more active such a
catalyst is in relation to a catalyst yielding a lower percentage
of hydrocarbon product boiling below the same given
temperature.
Accordingly, the present invention is directed to a catalyst and
catalytic hydrocracking process primarily of advantage in producing
a gasoline of improved octane quality, and more particularly, in
producing such gasoline without a major sacrifice in activity.
It is a major object of the invention to provide a catalytic
hydrocracking process utilizing a hydrocracking catalyst of
superior properties for producing a gasoline of improved octane
quality from gas oils and the like. A more specific object of the
invention is to provide a suitably active catalyst for use in a
catalytic hydrocracking process for treating hydrocarbon feedstocks
boiling primarily above 400.degree. F. to produce a light and/or a
heavy gasoline fraction of improved octane quality. These and other
objects of the invention will become more apparent in view of the
following description of the invention taken together with the
Examples and claims.
SUMMARY OF THE INVENTION
In accordance with the invention, it has now been found that a
hydrocarbon gasoline stream of increased octane number can be
recovered from the effluent of a hydrocracking zone wherein a
hydrocarbon feedstock is contacted with a hydrocracking catalyst
comprising a cracking component and a hydrogenation metal component
consisting essentially of a nickel component. The catalyst
preferably contains greater than 13 weight percent of nickel,
calculated as NiO. In another embodiment, the catalyst contains
nickel and at least one Group VIB metal hydrogenation component in
a mole ratio greater than 2 to 1, NiO to Group VIB metal trioxide.
Prepare crystalline molecular sieves that are acidic forms of Y
zeolites. It has been found that such hydrocracking catalysts are
significantly more effective for increasing octane numbers than
conventional hydrocracking catalysts, particularly when used in an
ammonia-cracking rich hydrocracking environment.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides for a hydrocarbon conversion
catalyst and its use, particularly in a process for producing a
hydrocarbon product containing light and heavy gasoline fractions
of improved octane quality. The catalyst contains at least one
nickel hydrogenation component combined with at least one cracking
component and may further contain at least one Group VIB metal
component. As will be shown hereinafter in Example I, a cracking
component combined with (1) greater than 13 weight percent of a
nickel component, calculated as NiO, (greater than 10.14 weight
percent, calculated as Ni) or (2) nickel in combination with a
Group VIB metal in a mole ratio greater than about 2 to 1 (NiO to
Group VIB metal trioxide), proves superior for imparting octane
boosting properties to the resulting catalyst as compared to
conventional catalysts.
The catalyst contains at least one nickel hydrogenation component,
such as the metal oxides or sulfides thereof, and typically in an
amount from about 5 to about 35 weight percent and preferably
between 13 and about 30 weight percent, calculated as NiO (i.e.,
about 3.9 to about 27.5, and preferably 10.14 to about 23.6,
calculated as the metal, respectively). The catalyst may also
contain one or more additional hydrogenation components, in
particular, the metals, oxides and sulfides of the Group VIB
elements, preferably tungsten and molybdenum, with the latter being
most preferred. When Group VIB metals are not present, it is
critical that the catalyst contain greater than 13 weight percent
of nickel components, calculated as NiO, (i.e., greater than 10.14
weight percent nickel, calculated as Ni). When Group VIB metals are
present, the catalyst preferably contains at least about 5 weight
percent, and more preferably at least 13 weight percent of nickel
components, calculated as NiO. The mole ratio of nickel components
to the Group VIB components is at least about 2 to 1, and usually
at least about 5 to 1, NiO to Group VIB metal trioxide.
The catalyst also contains a cracking component having sufficient
acidity to impart activity for cracking a hydrocarbon oil. Suitable
cracking components include silica-aluminas and crystalline
molecular sieves having cracking activity Crystalline molecular
sieves are preferred cracking components. The term "crystalline
molecular sieve" as used herein refers to any crystalline cracking
component capable of separating atoms or molecules based on their
respective dimensions. Crystalline molecular sieves may be zeolitic
or nonzeolitic. The term "nonzeolitic" as used herein refers to
molecular sieves whose frameworks are not formed of substantially
only silica and alumina tetrahedra. The term "zeolitic" as used
herein refers to molecular sieves whose frameworks are formed of
substantially only silica and alumina tetrahedra such as the
framework present in ZSM-5 type zeolites, Y zeolites, and X
zeolites. Examples of zeolitic crystalline molecular sieves which
can be used as a cracking component of the catalyst include Y
zeolite, fluorided Y zeolites, X zeolites, zeolite beta, zeolite L,
mordenite and zeolite omega. Examples of non-zeolitic crystalline
molecular sieves which may be used as a cracking component of the
catalyst include silicoalumino-phosphates, aluminophosphates,
ferrosilicates, titanium aluminosilicates, borosilicates and
chromosilicates.
The most preferred zeolitic crystalline molecular sieves are
crystalline aluminosilicate Y zeolites. U.S. Pat. No. 3,130,007,
the disclosure of which is hereby incorporated by reference in its
entirety, describes Y-type zeolites having an overall
silica-to-alumina mole ratio between about 3.0 and about 6.0, with
a typical Y zeolite having an overall silica-to-alumina mole ratio
of about 5.0. It is also known that Y-type zeolites can be
produced, normally by dealumination, having an overall
silica-to-alumina mole ratio above 6.0. Thus, for purposes of this
invention, a Y zeolite is one having the characteristic crystal
structure of a Y zeolite, as indicated by the essential X-ray
powder diffraction pattern of Y zeolite, and an overall
silica-to-alumina mole ratio above 3.0, and includes Y-type
zeolites having an overall silica-to-alumina mole ratio above about
6.0.
Typical Y zeolites in the sodium (or other alkali metal) form have
few or no acid sites and, thus, have little or no cracking
activity. The acidity of the Y zeolite may be increased by
exchanging the sodium in the Y zeolite with ammonium ions,
polyvalent metal cations, such as rate earth-containing cations,
magnesium cations or calcium cations, or a combination of both,
thereby lowering the sodium content. Such an ion-exchange may
reduce the stability of the Y zeolite and (typically in the case of
ammonium exchanges) the Y zeolite is then steam-treated at a high
temperature (i.e., about 600.degree. C. to about 800.degree. C.)
followed by further ion-exchange. For sufficient cracking activity,
the sodium (or other alkali metal) content of the Y zeolite is
generally reduced to less than about 1.0 weight percent, preferably
less than about 0.5 weight percent and most preferably less than
about 0.3 weight percent, calculated as Na.sub.2 O. Methods of
carrying out the ion exchange are well known in the art.
A preferred Y zeolite is one prepared by first ammonium exchanging
a Y zeolite to a sodium content between about 0.6 and 5 weight
percent, calculated as Na.sub.2 O, calcining ammonium exchanged
zeolite in the presence of at least 0.2 p.s.i. water vapor partial
pressure at a temperature between 600.degree. F. and 1,650.degree.
F. to reduce the unit cell size to a value in the range between
24.40 and 24.64 Angstroms, and then ammonium exchanging the zeolite
once again to replace at least 25 percent of the residual sodium
ions and obtain a zeolite product of less than 1.0 weight percent
sodium and preferably less than 0.6 weight percent sodium,
calculated as Na.sub.2 O. Such a Y zeolite is highly stable and
maintains a high activity. The zeolite is described in detail in
U.S. Pat. No. 3,929,672, the disclosure of which is hereby
incorporated by reference in its entirety. A preferred member of
this group is known as Y-82, a zeolitic aluminosilicate molecular
sieve available from the Linde Division of the Union Carbide
Corporation.
Another group of Y zeolites which may be used as a molecular sieve
in the catalyst of the invention is comprised of zeolites normally
having an overall silica-to-alumina mole ratio above about 6.0,
preferably between about 6.1 and about 15. The zeolites of this
group are prepared by dealuminating a Y-type zeolite having an
overall silica-to-alumina mole ratio below about 6.0 and are
described in detail in U.S. Pat. No. 4,503,023 issued to Breck et
al., and European patent application No. 84104815.0 published on
Nov. 7, 1984 as Publication No. 0 124 120 by Best et al., the
disclosures of which are hereby incorporated by reference in their
entireties. A preferred member of this group is known as LZ-210, a
zeolitic aluminosilicate molecular sieve available from the Linde
Division of the Union Carbide Corporation. LZ-210 zeolites and the
other zeolites of this group are conveniently prepared from a Y
zeolite starting material in overall silica-alumina mole ratios
between about 6.0 and about 15, although higher ratios are
possible. Preferred LZ-210 zeolites have an overall
silica-to-alumina mole ratio of about 6.1 to about 13.0. Typically,
the unit cell size is at or below 24.65 Angstroms and will normally
range between about 24.20 and about 24.65 Angstroms. LZ-210
zeolites having an overall silica-to-alumina mole ratio below 20
generally have a sorptive capacity for water vapor at least 20
weight percent based on the anhydrous weight of the zeolite.
Normally, the oxygen sorptive capacity at 100 mm mercury and
-183.degree. C. will be at least 25 weight percent. The LZ-210
class of zeolites have a composition expressed in terms of mole
ratios of oxides as:
wherein "M" is a cation having the valence "n" and "x" has a value
greater than 6.0.
In general, LZ-210 zeolites may be prepared by dealuminating Y-type
zeolites using an aqueous solution of a fluorosilicate salt,
preferably a solution of ammonium hexafluorosilicate. The
dealumination is accomplished by placing a Y zeolite, normally an
ammonium exchanged Y zeolite, into an aqueous reaction medium such
as an aqueous solution of ammonium acetate, and slowly adding an
aqueous solution of ammonium fluorosilicate. After the reaction is
allowed proceed, a zeolite having an increased overall
silica-to-alumina ratio is produced. The magnitude of the increase
is dependent at least in part on the amount of fluorosilicate
solution contacted with the zeolite and on the reaction time
allowed. Normally, a reaction time of between about 10 and about 24
hours is sufficient for equilibrium to be achieved. The resulting
solid product, which be separated from the aqueous reaction medium
by conventional filtration techniques, is a form of LZ-210 zeolite.
In some cases this product may be subjected to a steam calcination
by contacting the product with water vapor at a partial pressure of
at least 0.2 p.s.i.a. for a period of between about 1/4 to about 3
hours at a temperature between 900.degree. F. and about
1,500.degree. F. in order to provide greater crystalline
stability.
In addition to the zeolitic crystalline molecular sieves disclosed
herein and used in the Examples, other example of cracking
components that may be combined with metal hydrogenation components
include non-crystalline acidic materials such as the
silica-aluminas or silica-alumina dispersions described in U.S.
Pat. No. 4,097,365, the disclosure of which is incorporated by
reference in its entirety.
An example of non-zeolite crystalline molecular sieves also useful
as a cracking component in the composition of the invention is a
silicoaluminophosphate, known by the acronym "SAPO," described in
detail in U.S. Pat. No. 4,440,871, the disclosure of which is
hereby incorporated by reference in its entirety. Another useful
class of nonzeolitic crystalline molecular sieves is generally
referred to as crystalline aluminophosphates, designated by the
acronym "AlPO.sub.4." The structure and preparation of the various
species of aluminophosphates are discussed in U.S. Pat. Nos.
4,310,330 and 4,473,663, the disclosures of which are hereby
incorporated by reference in their entirety. Yet another class of
nonzeolitic molecular sieves suitable for use is known as
ferrosilicates, designated by the acronym "FeSO." A preferred
ferrosilicate denominated as FeSO-38 is disclosed in European
patent application No. 83220068.0 filed on Oct. 12, 1982 and
published on May 16, 1984 as Publication No. 0 108 271 A2, the
disclosure of which application is hereby incorporated by reference
in its entirety. Still other examples of nonzeolitic sieves include
rosilicates, chromosilicates and crystalline silicas. Borosilicates
are described in U.S. Pat. Nos. 4,254,247, 4,264,813 and 4,327,236,
the disclosures of which are hereby incorporated by reference in
their entireties. Chromosilicates are described in detail in U.S.
Pat. No. 4,405,502, the disclosure of which is also hereby
incorporated by reference in its entirety. A preferred crystalline
silica, essentially free of aluminum and other Group IIIA metals,
is a silica polymorph, i.e., silicalite, which may be prepared by
methods described in U.S. Pat. No. 4,061,724, the disclosure of
which is hereby incorporated by reference in its entirety.
The cracking component may be combined with a binder or matrix
material comprising a porous, inorganic refractory oxide component
or a clay component having essentially no cracking activity. To
prepare a catalyst, the cracking component is combined with the
porous, inorganic refractory oxide component, or a precursor
thereof, such as alumina, silica, titania, magnesia, zirconia,
borilia, silica-magnesia, silica-titania, other such combinations
and the like, with alumina being the most highly preferred.
Examples of precursors that may be used include peptized alumina,
alumina gel, hydrated alumina, and silica sols. Normally, the
porous, inorganic refractory oxide component or its precursor is
mixed or comulled with a cracking component in amounts such that
the final dry catalyst mixture will comprise (1) between about 5
weight percent and about 85 weight percent cracking component,
preferably between about 15 weight percent and about 80 weight
percent, and (2) between about 2 weight percent and about 75 weight
percent of porous, inorganic refractory oxide, preferably between
about 5 weight percent and about 60 weight percent. The comulled
mixture is then formed into particulates, usually by extrusion
through a die having openings of a cross sectional size and shape
desired in the final catalyst particles. For example, the die may
have openings therein in the shape of three-leaf clovers so as to
produce an extrudate material similar to that shown in FIGS. 8 and
8A of U.S Pat. No. 4,028,227, the disclosure of which is hereby
incorporated by reference in its entirety. Among preferred shapes
for the die openings are those that result in particles having
surface-to-volume ratios greater than about 100 reciprocal inches.
After extrusion, the catalyst particles are cut into lengths of
from 1/16 to 1/2 inch. The resulting particles are subjected to a
calcination at an elevated temperature, normally between about
600.degree. F. and about 1600.degree. F., to produce catalytic
particles of high crushing strength.
As will be shown hereinafter in the Examples, comparisons with
nickel and nickel-Group VIB metal catalysts indicate that the best
octane improvements occur in the absence of Group VIB metal. On the
other hand, the best activity occurs when Group VIB metal is
present. Present indications are that Group VIB metal functions to
increase activity, with, at most, a small sacrifice in octane
value--and in some cases, with an improvement in octane values, as
compared to catalysts containing only nickel as an active
hydrogenation metal. When Group VIB metals are present in the
catalyst, the activity is effectively improved when nickel and
Group VIB metals are contained in a mole ratio greater than about 5
to 1, preferably greater than about 9 to 1, more preferably greater
than about 17 to 1, and most preferably greater than about 25 to 1
(NiO to Group VIB metal trioxide). A mole ratio from about 9:1 to
about 60:1 is highly preferred. Nevertheless, at present, the best
results insofar as octane improvement is concerned have been with
catalysts containing at least one nickel component and no Group VIB
metals. Accordingly, a presently preferred catalyst for maximum
octane improvement comprises a hydrogenation metal consisting
essentially of one or more nickel components on a support
comprising a cracking component. A highly preferred catalyst
comprises a hydrogenation metal consisting essentially of greater
than 13 weight percent of one or more nickel components, calculated
as NiO, on a support containing a zeolitic aluminosilicate
molecular sieve known as Y-82. Another highly preferred catalyst
comprises a hydrogenation metal consisting essentially of at least
13 weight percent of one or more nickel components, calculated baas
NiO, and containing a Y-type zeolite known as LZ-210. Of course,
more active embodiments of such highly preferred catalysts further
contain one or more Group VIB metal components, particularly
molybdenum components, in the mole ratios to nickel hereinbefore
set forth. For instance, highly preferred nickel-Group VIB
catalysts, containing about 15 weight percent of nickel components,
calculated as NiO, and about 0.5 to about 3.0 weight percent of
molybdenum components, calculated as MoO.sub.3, in combination with
a cracking component, will contain nickel and molybdenum metals in
the preferred mole ratios. As stated above, such catalysts provide
increased activity with, at most, some sacrifice in the octane
value of the gasoline.
Although nickel and other hydrogenation components may be supplied
from essentially any source thereof, suitable inorganic compounds
for use herein include nickel nitrate, nickel acetate, nickel
carbonate, nickel oxide, ammonium heptamolybdate, molybdic
trioxide, ammonium metatungstate, and the like. Organometallic
compounds may be utilized such as cyclopentadienyl or carbonyl
nickel compounds.
The nickel or other hydrogenation components may be impregnated
into the extruded catalyst particles from a liquid solution
containing the desired component. Another method of combining the
hydrogenation metals with the cracking component is by mulling or
comulling hydrogenation metal compounds with the cracking
components and binding materials. In a preferred embodiment, the
extruded particles containing cracking components are impregnated
with an aqueous solution containing dissolved nickel
components.
The hydrogenation components, which will largely be present in
their oxide forms after calcination in air, may be converted to
their sulfide forms, if desired, by contact at elevated
temperatures in a reducing gas atmosphere comprising hydrogen
sulfide. Most commonly, the sulfiding is accomplished in situ, as
by placing the catalyst in its oxide form in the reactor vessel
wherein the hydrocracking reactions are to be performed and then
passing a mixture of hydrogen and hydrogen sulfide or hydrogen and
carbon disulfide through the catalyst bed under conditions of
elevated temperature. Alternatively, the catalyst may be placed in
the reactor vessel and then contacted, under hydrocracking
conditions and in the presence of a sulfur component, with the
hydrocarbon feedstock to be catalytically converted to lower
boiling hydrocarbons. The sulfur component may be an organosulfur
component present in the feedstock, or it may be hydrogen sulfide
added from an external source. Alternatively still, the hydrogen
sulfide may accompany the feedstock itself, as would be the case,
for example, if the hydrocracking operation is performed
immediately after hydrotreating. These and other equivalent methods
for activating the catalyst by conversion to the sulfide form may
be utilized in the invention.
The catalyst may be employed in any of several hydrocarbon
conversion processes wherein catalytic compositions containing
active metals on a support material are known to be catalytically
effective. Typical processes include dehydrogenation,
desulfurization, hydrodesulfurization, denitrogenation,
demetallization, isomerization, hydroisomerization, hydrocracking,
hydrodewaxing, reforming, and the like, with hydrocracking being
preferred. It is preferred that the catalyst contact a hydrocarbon
feedstock in the presence of hydrogen.
The term "hydrocarbon conversion" refers to any reaction wherein a
hydrocarbon compound changes chemical composition. As used herein,
"hydrocarbon" which consists of hydrogen and carbon, and
"hydrocompound carbon feedstock" or "hydrocarbon feed" refers to
any charge stock which contains greater than about 90 weight
percent carbon and hydrogen, calculated as the elements. Especially
preferred feedstocks include gas oils and feedstocks containing
normal paraffins.
The hydrocarbon conversion conditions employed to convert a
hydrocarbon feedstock will vary widely depending upon the process
in which the catalyst is used, the nature of the feed, and the
desired product. Most usually, the catalyst is maintained as a
fixed bed with the feedstock containing a hydrocarbon compound
passing downwardly therethrough, and the reactor is generally
operated under conditions which convert the feedstock into a
desired product containing at least one chemically-changed
derivative form of the hydrocarbon compound of the feedstock.
Operating conditions include a temperature from about 50.degree. F.
to about 1,000.degree. F., a pressure from atmospheric to about
4,000 p.s.i.g., and a space velocity of about 0.05 to about 25
(LHSV). It is preferred that the hydrocarbon conversion conditions
include the presence of added free hydrogen, with said conditions
including a hydrogen recycle rate usually about 1,000 to about
15,000, and preferably about 3,000 to about 10,000 standard cubic
feet per barrel (scf/bbl).
The catalyst disclosed herein is particularly useful for
hydrocracking a hydrocarbon oil containing hydrocarbons and/or
other organic materials to a product containing hydrocarbons and/or
other organic materials of lower average boiling point and lower
average molecular weight. The hydrocarbon feedstocks that may be
subjected to hydrocracking by the method of the invention include
all mineral oils and synthetic oils (e.g., shale oil, tar sand
products, etc.) and fractions thereof. Illustrative hydrocarbon
feedstocks include those containing components boiling above
550.degree. F., such as atmospheric gas oils, vacuum gas oils,
deasphalted vacuum and atmospheric residua, hydrotreated residual
oils, coker distillates, cycle oils, and catcracker distillates. A
preferred hydrocracking feedstock is a gas oil or other hydrocarbon
fraction having at least 50% by weight, and most usually at least
75% by weight, of its components boiling at temperatures above the
end point of the desired product, which end point, in the case of
heavy gasoline, is generally in the range from about 380.degree. F.
to about 420.degree. F. The most useful gas oil feedstock will
contain hydrocarbon components boiling above about 550.degree. F.
(that is, more than about 25 volume percent boils above 550.degree.
F.) with highly useful results being achieved with feeds containing
at least 25 percent by volume of components boiling between
600.degree. F. and 1,000.degree. F.
Also, included are petroleum distillates wherein at least 90
percent of the components boil in the range from about 300.degree.
F. to about 800.degree. F. The petroleum distillates may be treated
to produce both light gasoline fractions (boiling range, for
example, from about 50.degree. F. to about 185.degree. F.) and
heavy gasoline fractions (boiling range, for example, from about
185.degree. F. to about 400.degree. F.).
The process of the invention is most preferably utilized in
conjunction with a catalytic hydrotreating operation. That is, the
feedstock to be subjected to hydrocracking in the process of the
invention most usually comprises, and more usually still consists
essentially of, the entire effluent from a catalytic hydrotreater
wherein, in the presence of a hydrotreating catalyst usually
comprising Group VIII and VIB metal components on a porous
non-cracking refractory oxide, such as a sulfided catalyst
containing nickel and/or cobalt components plus molybdenum and/or
tungsten components on alumina, the sulfur and nitrogen components
in a hydrocarbon-containing liquid are converted by reaction with
hydrogen at elevated temperatures and pressures to hydrogen sulfide
and ammonia, respectively. In the preferred method of operation,
therefore, hydrotreating will precede hydrocracking, and thus, the
feedstock most usually subjected to hydrocracking in the process of
the present invention will be a hydrotreated feedstock, such as a
hydrotreated gas oil or a hydrotreated cycle oil. Such a
hydrotreated feedstock typically contains organonitrogen compounds
in a concentration in the range from about 0.1 to about 500 ppmw,
usually less than 100 ppmw, and preferably less than about 10 ppmw,
calculated as N, and contains organosulfur compounds in a
concentration less than about 500 ppmw, usually less than 100 ppmw,
and preferably between about 1 and 75 ppmw, calculated as S.
Although all or a portion of the effluent from a
hydrocarbon-containing stream passed through a hydrotreating zone
is passed through a hydrocracking zone containing the catalyst of
the invention, the process of the invention is not limited to this
particular flow scheme. For example, in another embodiment of the
invention, two separate hydrocracking zones may be utilized in
series in one reactor, or two or more reactors, with one zone
containing the catalyst of the invention and the other(s)
containing the same or a different hydrocracking catalyst. Because
of the combined presence of nickel and the cracking component in
one of the catalysts, octane numbers of both light gasoline and
heavy gasoline fractions are increased in the products obtained
from a hydrocarbon feed that passes through the reactor.
In the process of the invention, the hydrocracking conditions are
adjusted so as to obtain a substantial degree of cracking per pass
of hydrocarbon feed over the catalyst. Usually, the cracking per
pass is such as to convert a significant portion, ordinarily at
least 30% by volume, preferably at least 35% by volume, of the
hydrocarbon-containing components boiling above about 400.degree.
F. to hydrocarbon products boiling below about 400.degree. F. Under
preferred cracking conditions, and with a typical gas oil, the
product distribution is such that, of the products boiling at a
temperature less than about 400.degree. F., the gasoline product
boiling between 50.degree. F. and the end point of a typical
gasoline fraction (i.e., about 185.degree. F.) and the gasoline
product boiling between about 185.degree. F. and the end point of a
typical heavy gasoline fraction (i.e., about 400.degree. F.) both
may comprise significant proportions.
The exact conditions, of course, required to produce a desired
result in any given hydrocarbon conversion process will depend
primarily on the feedstock and the desired product, with the
boiling point characteristics of the feedstock and desired product
being particularly important factors in determining the conditions
of operation. In general, however, the conditions of operation for
hydrocracking gas oil feedstocks and the like in the process of the
invention will fall into the following ranges:
TABLE I ______________________________________ Suitable Preferred
______________________________________ Temperature, .degree. F.
450-950 500-800 Pressure, p.s.i.g. 500-3,500 1,000-3,000 LHSV
0.1-10.0 0.5-3.0 H.sub.2 /Oil, MSCF/bbl 1-10 2-8
______________________________________
Typical reactions involving hydrocarbon compounds of the feed which
occurs under the above-mentioned conditions include the conversion
of cyclic compounds to aliphatic compounds. For instance,
alicyclic, aromatic and/or heterocyclic compounds are converted to
straight- or branchedchain paraffin compounds. Also, long chained
aliphatic compounds are converted to shorter chain compounds. The
yield of C.sub.4 to 400.degree. F. gasoline is usually at least
about 50 percent and preferably at least about 70 percent by volume
on a once-through basis. Although it is contemplated that the
hydrocracking process of the invention may be carried out on a
once-through basis, with collection of unconverted feed components,
it is sometimes more desirable and preferable to operate with
recycle of unconverted feed components boiling above the maximum
desired product end point.
The hydrocracking catalysts described above are much more effective
for increasing the octane quality of gasoline than conventional
hydrocracking catalysts in the presence of ammonia. It is a
preferred embodiment of the invention, therefore, to use the
catalyst in a hydrocracking zone under ammonia-rich hydrocracking
conditions. The phrase "ammonia-rich" as used herein refers to the
situation where there is more than 100 ppmw ammonia, based on the
feedstock, present in the hydrocracking zone. As the ammonia
concentration is increased, it generally causes more deactivation
of hydrocracking catalysts, but the present catalysts (nickel only
or nickel-Group VIB versions) remain active and provide gasoline of
increased octane value even when the ammonia is present in the
hydrocracking zone in a concentration greater than 200 ppmw and
even when greater than 1,000 ppmw. In a preferred embodiment of the
hydrocracking process of the invention in which only one
hydrocracking zone is utilized in series with, and a downstream of,
a hydrotreating zone, the feed to the hydrocracking zone will not
be treated to remove the ammonia produced in the hydrotreating zone
below 200 ppmw. In another embodiment in which two hydrocracking
zones are in series downstream of a hydrotreating zone, such as the
process described in U.S. Pat. No. 4,565,621, the disclosure of
which is hereby incorporated by reference in its entirety, the
catalyst will normally be used in the first hydrocracking zone
which directly receives the ammonia-containing effluent from the
hydrotreating zone. Since ammonia is removed from the process by
water scrubbing. the effluent from the first hydrocracking zone
before the unconverted portion of the effluent is passed to the
second hydrocracking zone, the second hydrocracking zone has an
essentially ammonia-free hydrocracking atmosphere in which there is
normally no more than about 50 ppmw ammonia, based on the
feedstock, present.
In the hydrocracking process of the invention, the effluents from
one or more hydrocracking zones are subjected to distillation to
separate the lower boiling fractions from the higher boiling
fractions which are recycled to the last hydrocracking zone. A
light gasoline fraction boiling in the range between about
50.degree. F. and about 185.degree. F. is removed from the
distillation column along with a heavier gasoline fraction boiling
in the range between about 185.degree. F. and about 400.degree. F.
(Operation with recycle under ideal conditions converts the
400+.degree. F. fraction to extinction, i.e., a 100% conversion to
products boiling below the maximum desired temperature of the
product. More usually, however, one must operate with a bleed of
unconverted feed components, resulting in a conversion over 90% but
not quite to extinction.) In conventional hydrocracking processes,
the light gasoline fraction is usually blended into the final
gasoline product; however, it is sometimes passed downstream where
it is subjected to isomerization to increase its research and motor
octane numbers so that the fraction can be more effectively used in
gasoline blending. The heavier gasoline fraction, which will
normally have research and motor octane numbers somewhere in the
40's to low 60's, is typically subjected to reforming to increase
the octane numbers to values which would enable the reformed
fractions to be directly used in gasoline blending. By employing
the process of the invention in which the hydrocracking catalysts
disclosed herein are used in at least one hydrocracking zone, the
motor and research octane numbers of the resultant light gasoline
fraction will typically be sufficiently high to allow the fraction
to be used directly as a gasoline blending fraction, thus reducing
the need for expensive isomerization. Moreover, the heavy gasoline
fraction produced in such a process will possess increased research
and motor octane numbers. This means that the reformer can be
operated under less severe conditions to obtain the desired octane
number increase while decreasing the loss of volume yield which
would be incurred at the more severe reforming conditions than
would otherwise be required Alternatively, the reformer can be
operated at a constant volume yield and an increased product octane
is obtained.
An advantage of the catalyst employed herein is that its properties
allow a petroleum refiner to also employ the catalyst in a
downstream isomerization process such as the hydroisomerization of
normal paraffins, particularly n-pentane and n-hexane compounds, to
produce high yields of paraffin isomers. An exemplary isomerization
process involves isomerizing the components of a light gasoline
fraction to effect an increase in motor and research octane
numbers. In such processes, the catalyst is employed under
isomerizing conditions and often in the presence of sulfur
impurities in the feedstock. Typically the catalyst is employed to
isomerize a feedstock containing aliphatic hydrocarbons
(particularly paraffins) and organosulfur compounds at a
temperature in the range from about 50.degree. F. to about
575.degree. F. and a pressure from atmospheric to about 500
p.s.i.g. in the presence of hydrogen to produce a hydrocarbon
product containing essentially no sulfur and an inincreased yield
of paraffin isomer compounds compared to the feedstock. More
specifically, a catalyst comprising a hydrogenation metal component
consisting essentially of nickel components and a Y zeolite such as
LZ-210 may be contacted by a light gasoline feedstock containing
sulfur, n-pentane and/or n-hexane in a reactor operated at about
450.degree. F. to about 575.degree. F. and a pressure in the range
from about 200 p.s.i.g. to about 350 p.s.i.g. to produce a
hydrocarbon product containing essentially no sulfur, but
containing C.sub.5 and/or C.sub.6 branched isomer compounds in a
concentration greater than that in the feedstock. Consequently the
hydrocarbon product has an octane number greater than that of the
feedstock. The property of the catalyst composition of the present
invention, with respect to simultaneously desulfurizing and
isomerizing a hydrocarboncontaining oil, is further disclosed in
co-pendng U.S. patent application Ser. No. 074,294, filed July 16,
1987, Dr. Suheil F. Abdop and Peter Kokayeff, entitled
"Desulfurization and Isomerization of n-Paraffins," the disclosure
of which application is hereby incorporated by reference in its
entirety.
The invention is further illustrated by the following examples
which are illustrative of specific modes of practicing the
invention and are not intended as limiting the scope of the
invention defined by the appended claims.
EXAMPLE I
A blend of hydrotreated and partially hydrocracked gas oil having
the chemical and physical properties shown in the following Table
II:
TABLE II ______________________________________ Gas Oil
Characteristics Distillation Vol. % .degree. F.
______________________________________ IBP/5 .sup. 325/402 Gravity,
.degree. API 38.5 10/20 410/425 Sulfur, XRF, ppmw .about.0.1 30/40
468/500 Nitrogen, ppmw .about.0.1 50/60 532/561 70/80 591/623 90/95
665/705 Total Aromatics, vol. % 25.6 EP/% Rec. 768/98.9
______________________________________
is passed in fourteen runs (runs 1 through 14) on a once-through
basis through an isotermal reactor vessel containing a sample of
catalyst particles. Operating conditions are as follows: 1.7 LHSV,
1,450 p.s.i.g., a once-through hydrogen flow of 8,000 scf/bbl. The
temperature of the reactor is adjusted in runs 8 through 14 to
convert the feedstock to a product having an API gravity of
47.0.degree. (i.e., about 40 volume percent conversion of feed
components to products). In addition, tert-butyl amine and
thiophene are added to the reactor in runs 8 through 14 in amounts
commensurate with the amounts of NH.sub.3 and H.sub.2 S,
respectively, that would be present in the entire effluent from
hydrotreating the gas oil blend from which the feedstock of Table
II was derived, i.e., hydrocracking is simulated in an H.sub.2 S
and NH.sub.3 -containing atmosphere providing a gas oil containing
about 0.5% by weight sulfur and 0.2 by weight of nitrogen (i.e., an
ammonia-rich feedstock). To simulate hydrocracking in a H.sub.2
S-containing atmosphere, thiophene, but no tert-butyl amine, is
added to the reactor in runs 1 through 7 (i.e., an
ammonia-deficient feedstock) and the temperature is adjusted to
convert the feedstock to a product having an API gravity of
49.5.degree. (i.e., about 55 volume percent conversion of feed to
product components). Thus, the conditions under which the catalysts
are tested simulate those one would expect to pertain in a
hydrocracking vessel employed in an integral
hydrotreating-hydrocracking operation wherein the entire effluent
from the hydrotreater, plus added hydrogen, is passed to the
hydrocracker for further refinement. In this case, conversion is
primarily to a light and heavy gasoline product. (In this
simulation, the crack per pass in the hydrocracking zone itself, as
stated above, is about 55 vol. % in runs 1 through 7 and 40 vol. %
in runs 8 through 14; but the overall crack per pass through the
integral hydrotreating-hydrocracking system, based on the
unhydrotreated feedstock, is 60 vol. %.)
The compositions of the catalysts tested in accordance with the
foregoing procedure are specified in Table III. As shown, each of
the catalysts (conventional catalysts R, F, and D and catalysts of
the invention A, B, C and E) contains nickel or nickel plus
molybdenum active components, and the supports of the catalysts
contain the same proportion of one of two stabilized zeolites, one
being LZ-210, a proprietary zeolite of Union Carbide, and the
second, a stabilized Y zeolite, Y-82, prepared in accordance with
the method of U.S. Pat. No. 3,929,672 herein incorporated by
reference in its entirety. The two zeolites may be distinguished
from each other at least by their silica-to-alumina ratios. The
stabilized Y zeolite, Y-82, is hydrophillic and has a
silica-to-alumina mole ratio about 5.8. The LZ-210 zeolites have a
silica-to-alumina mole ratio higher than that of Y-82, that is,
about 6.5 and 9.0.
In addition to containing one of the two specified zeolites, the
catalysts set forth in Table III are further composed of an alumina
binder material.
Each of the foregoing catalysts is prepared by comulling the
zeolites with an alumina hydrogel. The comulled paste is extruded
in particulate form having a cross-sectional cylindrical shape. The
particulates, of a length between about 1/4 and 1/2 inch, are dried
and calcined in air. The particulates are ten impregnated with an
aqueous solution of nickel nitrate in an amount sufficient to
produce final Catalysts A, C, D and E having the weight percent set
forth in Table III. In preparing Catalysts R and B, an aqueous
solution containing ammonium heptamolybdate and nickel nitrate is
used to impregnate the particulates. Conventional Catalyst F is
prepared by impregnating the particles with an aqueous solution
containing nickel nitrathe and ammonium metatungstate. All the
impregnated particulates are dried, calcined and sulfided in an
identical manner.
TABLE III
__________________________________________________________________________
Composition Metals, wt. % Mole Ratio Relative Light Gasoline.sup.5
Heavy Gasoline.sup.6 Group NiO/MO.sub.3 Support Activity, Octane
Number Octane Number Run No./Cat. NiO VIB *** Zeolite (SiO.sub.2
/Al.sub.2 O.sub.3) .degree.F..sup.1,2 Research.sup. Motor.sup.4
Research.sup.3 Motor.sup.4
__________________________________________________________________________
1 Cat R 5.0 15.0* 0.64 Y-82 (5.8) Ref 84.1 81.8 60.6 61.9 2 Cat A
15.0 -- -- Y-82 (5.8) Ref + 20 85.6 83.1 62.2 64.2 3 Cat B 15.0
3.0* 9.6 Y-82 (5.8) Ref + 4 84.3 80.2 61.5 59.8 NH.sub.3 4 Cat D
5.0 -- -- Y-82 (5.8) Ref + 30 83.3 80.1 64.2 63.7 Def. 5 Cat C 15.0
-- -- LZ-210 (9.0) Ref + 42 83.4 80.1 54.4 56.0 6 Cat E 15.0 -- --
LZ-210 (6.5) Ref + 13 84.9 80.2 64.0 62.8 7 Cat F 4.0 22.0** 0.56
LZ-210 (9.0) Ref + 24 86.9 82.3 56.7 57.2 8 Cat R 5.0 15.0* 0.64
Y-82 (5.8) Ref 80.8 78.7 59.1 59.0 9 Cat A 15.0 -- -- Y-82 (5.8)
Ref + 3 85.9 82.4 63.9 63.8 10 Cat B 15.0 3.0* 9.6 Y-82 (5.8) Ref +
1 82.0 78.5 62.6 61.5 NH.sub.3 11 Cat D 5.0 -- -- Y-82 (5.8) Ref +
11 84.4 80.1 64.8 63.0 Rich 12 Cat C 15.0 -- -- LZ-210 (9.0) Ref +
4 85.3 81.6 64.5 58.8 13 Cat E 15.0 -- -- LZ-210 (6.5) Ref + 8 85.1
81.4 65.6 62.8 14 Cat F 4.0 22.0** 0.56 LZ-210 (9.0) Ref - 16 81.3
79.0 56.7 57.2
__________________________________________________________________________
.sup.1 The activity data indicate the relative operating temp.
after 100 hrs. of run for runs 1-7 to obtain a product having an
API Gravity of 49.5.degree. . .sup.2 The activity data indicate the
relative operating temp. after 80 hrs. of run for runs 8-14 to
obtain a product having an API Gravity of 47.0.degree.. .sup.3
Octane numbers determined according to ASTM method D2699. .sup.4
Octane numbers determined according to ASTM method D2700. .sup.5
Light gasoline boiling range is 50.degree. F. to 185.degree. F.
.sup.6 Heavy gasoline boiling range is 185.degree. F. to
400.degree. F. *Molybdenum, calculated as MoO.sub.3 **Tungsten,
calculated as WO.sub.3 - ***M denotes Mo or W (i.e., MoO.sub.3 or
WO.sub.3)
The data in Table III show that Catalysts A and B of the invention
(containing Y-82 zeolite) exhibit octane boosting properties as
compared to conventional Catalysts R and D. Also, Catalyst B,
having a NiO/MoO.sub.3 mole ratio greater than 2 to 1, demonstrates
an activity advantage over Catalyst A and, under ammonia-rich
conditions, demonstrates octane boosting properties over Catalyst R
and about equivalent to Catalyst R under ammonia-deficient
conditions. Furthermore, Catalysts C and E of the invention
(containing LZ-210 zeolite) exhibit octane boosting properties as
compared to conventional Catalyst F.
The data obtained from the runs indicate that a catalyst containing
a zeolite Y-82 support and a hydrogenation metal consisting
essentially of a nickel component (such as Catalyst A) exhibits a
superiority over Catalyst R in increasing the octane numbers of
both light and heavy gasoline products obtained from the feedstock
under both ammonia-rich and ammonia-deficient conditions. For
instance, the octane numbers of the light gasoline fraction are
from 3.7 to 5.1 numbers higher in run no. 9 (Catalyst A) than run
no. 8 (conventional Catalyst R containing 5 NiO, 15 MoO.sub.3
supported on Y-82 zeolite) under ammonia-rich conditions. Also, the
octane numbers of the heavy gasoline fraction are about 4.8 numbers
higher in run no. 9 vs. run no. 8. Such boosts in the octane rating
in run no. 9 vs. run no. 8 are observed while the activity of
Catalyst A is 3.degree. F. less under ammonia-rich conditions.
Under the ammonia-deficient conditions of run nos. 1 and 2,
Catalyst A exhibits an octane increase from 1.3 to 1.5 numbers for
light gasolines and from 1.6 to 2.3 for heavy gasolines compared to
Catalyst R.
Furthermore, when LZ-210 is used in Catalyst C of the invention,
the octane numbers are also improved significantly in run no. 12
vs. run no. 14, i.e., from 2.6 to 4.0 numbers higher than
conventional Catalyst F (containing nickel and nickel on LZ-210)
for light gasoline fractions and 1.6 to 7.8 numbers higher for
heavy gasoline fractions under ammonia-rich conditions. Moreover,
when the silica-to-alumina ratio of LZ-210 is decreased from 9.0
(in Catalyst C) to 6.5 (in Catalyst E), the octane number
improvement for heavy gasoline fractions by Catalyst E vs. Catalyst
F (run no. 13 vs. run no. 14) is even greater than Catalyst C vs.
Catalyst F under ammonia-rich conditions of run no. 13 vs. run no.
12. Under ammonia-deficient conditions (run no. 6 vs. run nos. 5 or
7), Catalyst E also provides a substantial improvement of 7.3 to
9.6 research octane numbers and 5.6 to 6.8 motor octane numbers for
heavy gasoline fractions over Catalyst C or F and is more active by
29.degree. F. and 11.degree. F., respectively.
When the catalyst contains a cracking component and one or more
hydrogenation components consisting essentially of more than 13
weight percent of nickel, calculated as NiO, the octane numbers of
the light gasoline fraction are consistently higher than those for
a catalyst containing the same cracking component and a
hydrogenation component consisting essentially of lesser amounts of
nickel. The comparison of run no. 2 vs. run no. 4 and the
comparison of run no. 9 vs. run no. 11 demonstrathe such results in
both ammonia-rich and ammonia-deficient conditions. Catalyst A
(containing Y-82 zeolite and consisting essentially of 15 weight
percent of nickel, as NiO) exhibits an improvement over Catalyst D
(containing Y-82 zeolite and consisting essentially of 5 weight
percent of nickel, as NiO) of 2.3 to 3.0 numbers (run no. 2 vs. run
no. 4) and 1.5 to 2.3 numbers (run no. 9 vs. run no. 11) for light
gasoline fractions. It is clear from the data that a catalyst
containing relatively large amounts of nickel components, i.e.,
greater than 13 weight percent, and preferably greater than about
14 weight percent, calculated as NiO, provides an unusual
improvement in gasoline octane quality as compared to the same
catalyst containing less than 13 weight percent of nickel, as
NiO.
The data from the runs also indicathe that a NiO/MoO.sub.3 mole
ratio greater than 2 to 1 in the catalyst of the invention provides
improved octane numbers for both light and heavy gasoline
fractions. Under ammonia-rich conditions, the octane numbers of the
light and heavy gasoline fractions obtained from run no. 10 (using
Catalyst B having 15 NiO and 3 MoO.sub.3, i.e., NiO/MoO.sub.3 mole
ratio of 9.6 to 1) are typically higher than those obtained from
run no. 8 (using Catalyst R having 5 NiO and 15 MoO.sub.3,
Ni/MoO.sub.3 mole ratio of 0.64 to 1), i.e., an improvement up to
1.2 numbers for light gasoline fractions and up to 3.5 numbers for
heavy gasoline fractions (run. no. 10 vs. run no. 8). Furthermore
in the comparison of Catalyst B vs. Catalyst A (containing no
molybdenum), the data further show that the octane numbers of the
light and heavy gasoline fractions obtained from run no. 9
(Catalyst A) are consisthently higher than those obtained from run
no. 10 (Catalyst B) and the activity nearly equivalent, i.e., under
ammonia-rich conditions an improvement of 3.3 to 3.9 numbers for
light gasoline fractions and 1.3 to 2.3 numbers for heavy gasoline
fractions (run no. 9 vs. run no. 10). Also, Catalyst A is only
2.degree. F. less active than Catalyst B. On the other hand, under
ammonia-deficient conditions, Catalyst A exhibits an improvement of
1.3 to 2.9 numbers for light gasoline fractions and 0.7 to 4.4
numbers for heavy gasoline fractions vs. Catalyst B (see run no. 3
vs run no. 2); however, Catalyst A is about 16.degree. F. less
active than Catalyst B under such ammonia-deficient conditions. The
data obtained from the experiment indicathe that Catalyst B of the
invention (having a NiO/MoO.sub.3 mole ratio of 9.6 to 1) is useful
for boosting octane and has an activity advantage over the
catalysts containing no molybdenum; however, under suitable
conditions, Catalyst A of the invention can outperform Catalyst B
in increasing octane values in the gasoline product.
EXAMPLE II
Another blend of hydrotreated and partially hydrocracked gas oil
having the chemical and physical properties shown in Table IV:
TABLE IV ______________________________________ Gas Oil
Characteristics Distillation Vol. % .degree. F.
______________________________________ IBP/5 .sup. 234/363 Gravity,
.degree. API 35.7 10/20 369/388 Sulfur, XRF, ppmw .about.0.1 30/40
401/450 Nitrogen, ppmw .about.0.1 50/60 579/614 70/80 665/714 90/95
760/795 Total Aromatics, vol. % 20.9 EP/% Rec. 850/99.1
______________________________________
is passed in then runs (runs 15 through 24) in the same manner as
disclosed in Example I. Runs 15 through 19 are operated in the same
manner as runs 1 through 7 in Example I, with runs 20 through 24
operated in the same manner as runs 8 through 14 in Example I.
The compositions of the catalysts thested are specified in Table V.
Catalysts R and A are prepared in the same manner as in Example I
and contain the same nominal compositions. Catalyst G is prepared
in the same manner as Catalyst B in Example I, except a smaller
portion of ammonium heptamolybdathe is mixed with the other
matherials and the final nominal composition of Catalyst B contains
1.0 weight percent of molybdenum, calculated as MoO.sub.3.
Catalysts L and FA are prepared in the same manner as respective
Catalysts C and F in Example I, except the LZ-210 has a
silica-to-alumina ratio of 12.
TABLE V
__________________________________________________________________________
Composition Metals, wt. % Mole Ratio Relative Light Gasoline.sup.5
Heavy Gasoline.sup.6 Group NiO/MO.sub.3 Support Activity, Octane
Number Octane Number Run No./Cat. NiO VIB *** Zeolite(SiO.sub.2
/Al.sub.2 O.sub.3) .degree.F..sup.1,2 Research.sup.3 Motor.sup.4
Research.sup.3 Motor.sup.4
__________________________________________________________________________
15 Cat R 5.0 15.0* 0.64 Y-82 (5.8) Ref 83.1 81.5 53.1 57.1 16 Cat A
15.0 -- -- Y-82 (5.8) Ref + 35 84.5 81.9 58.0 61.1 NH.sub.3 17 Cat
G 15.0 1.0* 28.9 Y-82 (5.8) Ref + 15 85.1 82.4 57.7 59.5 Def. 18
Cat L 15.0 -- -- LZ-210 (12) Ref + 54 85.2 83.0 59.3 61.1 19 Cat FA
4.0 22.0** 0.56 LZ-210 (12) Ref + 22 83.3 81.6 56.2 58.2 20 Cat R
5.0 15.0* 0.64 Y-82 (5.8) Ref 81.0 79.1 50.6 54.6 21 Cat A 15.0 --
-- Y-82 (5.8) Ref + 11 83.8 80.8 55.1 59.1 NH.sub.3 22 Cat G 15.0
1.0* 28.9 Y-82 (5.8) Ref + 6 84.1 81.6 56.0 58.8 Rich 23 Cat L 15.0
-- -- LZ-210 (12) Ref + 6 83.5 80.9 55.9 59.0 24 Cat FA 4.0 22.0**
0.56 LZ-210 (12) Ref - 14 80.3 78.7 49.0 52.7
__________________________________________________________________________
.sup.1 The activity data indicate the relative operating temp.
after 100 hrs. of run for runs 15-19 to obtain a product having an
API Gravity of 49.5.degree.. .sup.2 The activity data indicate the
relative operating temp. after 80 hrs. of run for runs 20-24 to
obtain a product having an API Gravity of 47.0.degree.. .sup.3
Octane numbers determined according to ASTM method D2699. .sup.4
Octane numbers determined according to ASTM method D2700. .sup.5
Light gasoline boiling range is 50.degree. F. to 185.degree. F.
.sup.6 Heavy gasoline boiling range is 185.degree. F. to
400.degree. F. *Molybdenum, calculated as MoO.sub.3 **Tungsten,
Tungsten, calculated as WO.sub.3 ***M denotes Mo or W (i.e.,
MoO.sub.3 or WO.sub.3)
The data in Table V show that Catalysts A and G of the invention
exhibit octane boosting properties compared to conventional
Catalyst R. Also, Catalyst G, having a NiO/MoO.sub.3 mole ratio of
the metals greater than 2 to 1, demonstrathes an activity advantage
over Catalyst A and, under both ammonia-rich and ammonia-deficient
conditions, demonstrathes octane boosting properties over Catalyst
R. Furthermore, Catalyst L of the invention exhibits octane
boosting properties as compared to conventional Catalyst FA.
The data obtained from the runs in Table V indicathe that Catalyst
A (containing nickel and no molybdenum) continues to maintain its
superiority over conventional Catalyst R for increasing the octane
numbers of light gasoline products obtained from a similar
feedstock to that in Example I. For instance, in comparing run nos.
16 and 21 (Catalyst A) to run nos. 15 and 20 (Catalyst R),
respectively, the octane numbers of the light gasoline fraction are
greater by up to 2.8 numbers for Catalyst A than for Catalyst R and
for the heavy gasoline fraction are greater by up to 4.9 numbers.
However, the activity of Catalyst A relative to Catalyst R declines
by 35.degree. F. in run no. 16 vs. run no. 15 and by 11.degree. F.
in run no. 21 vs. run no. 20.
Catalyst G (containing nickel and only 1.0 weight percent of
molybdenum, i.e. NiO/MoO.sub.3 mole ratio of 28.9) also exhibits a
superiority over Catalyst R in increasing the octane numbers of
both light and heavy gasoline fractions. For instance, the octane
numbers of the light gasoline fraction are up to 2.0 and 3.1
numbers higher in run nos. 17 and 22 (vs. run nos. 15 and 20,
respectively) and the octane numbers of the heavy gasoline fraction
are up to 4.6 and 5.4 numbers higher.
The data in Table V also indicathe that Catalyst G exhibits a
superiority in activity and at least maintains, or in some cases
improves, the octane numbers of gasoline products obtained from the
feedstock as compared to a catalyst (Catalyst A) containing a
cracking component and a hydrogenation component consisting
essentially of nickel components. For instance, the octane numbers
of the light gasoline fraction are from 0.5 to 0.6 numbers higher
in run no. 17 (Catalyst G) than run no. 16 (Catalyst A) and 0.3 to
0.8 higher in run no. 22 than run no. 21.
Catalyst G also exhibits a substantial activity advantage compared
to Catalyst A. The activity for Catalyst G in run no. 17 is only
15.degree. F. less than Catalyst R whereas Catalyst A exhibits a
35.degree. F. decline in run no. 16. However, unlike the runs in
Example I, this time the nickel-only catalyst (Catalyst A) and the
nickel-molybdenum catalyst (Catalyst G) are about equal for
boosting octane. Furthermore, under ammonia-rich conditions,
Catalyst G exhibits an activity advantage of 5.degree. F. (compared
to Catalyst A) in the comparison of run no. 22 vs. run no. 21.
Thus, the data obtained from the experiment indicathe that,
although Catalyst A of the invention is useful for improving
octane, Catalyst G of the invention is useful for improving octane
and is also far more active for converting gas oil feedstocks to
gasoline.
Both Catalyst L and conventional Catalyst FA contain supports
having an LZ-210 zeolite with a silica-to-alumina ratio of 12.0.
Catalyst L (containing nickel) provides a consisthent boost in both
research and motor octane numbers compared to conventional Catalyst
FA (containing nickel and tungsthen). The comparison of run no. 18
vs. run no. 19 under ammonia-deficient conditions and run no. 23
vs. run no. 24 under ammonia-rich conditions illustrathes that
Catalyst L improves the octane quality of the products from 1.6 to
3.1 numbers under ammonia-deficient conditions and from 2.2 to 6.9
numbers under ammonia-rich conditions.
Thus, the data for the experiment indicathe that Catalysts A and L
of the invention have superior octane boosting properties (compared
to respective Catalysts R and FA) provided by the presence on the
catalysts of only nickel components (at least 13 weight percent,
NiO) in combination with Y-82 and LZ-210 cracking components,
respectively. Furthermore, the data indicathe that the
nickel-molybdenum Catalyst G, is more active than the nickel-only
version (Catalyst A) and still exhibits octane boosting properties
compared to a conventional nickel-molybdenum catalyst (Catalyst
R).
In view of the foregoing description of the invention including the
examples thereof, it is evident that many althernatives,
modifications, and variations can be made by those skilled in the
art without departing from the concept of the present invention.
For instance, the catalyst may be employed in other hydrocarbon
conversion processes, such as for hydrodewaxing or isomerizing a
feedstock containing hydrocarbon compounds. Accordingly, it is
intended in the invention to embrace all such alternatives,
modifications, and variations as may fall within the scope of the
appended claims.
* * * * *